The octagonal gasket is installed in the ladder shaped groove on the flange surface. When the connecting bolt is tightened, it is compressed axially and pressed against the upper and lower ladder shaped grooves, causing plastic deformation and forming an annular sealing band, establishing the initial seal. After the pressure is increased, the ring gasket expands radially under the action of the medium pressure. The gasket is more tightly attached to the inclined surface of the trapezoidal groove, creating a self tightening effect. However, the increase in medium pressure can also cause deformation of the flange and connecting bolts, resulting in relative separation between the sealing surfaces and a relative decrease in the sealing ratio of the gasket. Therefore, the gasket can be considered a semi self tight seal.
The following is the extension content of the octagonal cushion:
Octagonal pad performance characteristics:
1. High temperature and high pressure resistance, suitable for high-pressure flanges;
2. Durable and reliable sealing;
3. Adapt to working conditions with fluctuating pressure and temperature;
Application scope of octagonal gasket: It is usually used for pipe flanges, tower tanks, pressure vessels, high-speed joint surfaces, high-temperature and high-pressure valves, and covers for high-temperature and high-pressure steam, gas, and solvents. Wellhead equipment and seals on Christmas trees in the petroleum and natural gas industry